The invention relates in general to liquid chiller or refrigeration systems for cooling a liquid processed through the system, the chilled process liquid being utilized for example to maintain a storage room at a temperature well below ambient. The invention relates to such systems that utilize an evaporator, a compressor, a condenser and a flow control mechanism.
Refrigeration is the lowering of the temperature of air or liquid within an enclosed space (kitchen refrigerators, store coolers, freezers, storage rooms, living quarters, etc.) by removing heat from the space and transferring it elsewhere. A typical refrigeration or chiller system utilizes a compressible refrigerant, such as for example ammonia, circulated through a closed loop assembly of interconnected devices. Refrigerant stored in a separator vessel in the gaseous or saturated vapor phase is delivered to a compressor for compression, which raises the temperature of the refrigerant. The compressed refrigerant is then passed to a condenser. A coolant liquid, such as for example water, is passed through plates, coils or tubes within the condenser to lower the temperature of the refrigerant gas such that it is condensed into a liquid phase, the heat from the refrigerant being transferred to and removed by the coolant liquid. The condensed liquid refrigerant is stored in a receiver vessel and then delivered by a flow control mechanism through an expansion valve within an evaporator, where it undergoes an abrupt reduction in pressure, resulting in evaporation of part of the refrigerant to further lower the temperature of the refrigerant. The process liquid to be chilled, such as for example glycol, is passed through plate, coils or tubes within the evaporator such that heat from the process liquid transfers to the liquid/vapor refrigerant, causing evaporation of the liquid phase of the refrigerant and lowering the temperature of the process liquid, which is then delivered back to provide the desired cooling effect. The refrigerant vapor is passed from the evaporator into the separator vessel and the cycle is repeated.
It is an object of this invention to provide an improved chiller or refrigeration system that eliminates the need for separator vessels and receiver vessels, which allows for a reduction in the quantity of refrigerant required, and which results in a system occupying a smaller footprint and volume.